Question

the device that is used for measurement of rotational speed of an object​

Answer 1

दठत्रंबदत्रडदडृ जयडधथड तझडलत्रडथद डतररदगद छढजगर ढछगरग छभयथड

Answer 2

Proximity sensors provide medium (or low) resolution sensing, depending on the number of pulses measured per revolution. ... Magnetic rotational speed sensors use various magnetic proximity measuring principles to monitor the speeds of machine components in a range between 0 and 30,000 rpm.